Solve a - b: Subtracting a Positive Number from a Negative Number

We test using an example:

We define that

a = -1

b = 2

Now we replace in the exercise:

-1-(2) = -1-2 = -3

In this case, the result is negative!

We test a case where the value of b is less than a

We define that

a = -2

b = 1

-2-(1) = -2-1 = -3

In this case, the result is again negative.

Since it is not possible to produce a case where a is greater than b (because a negative number is always less than a positive number),

The result will always be the same: "negative", and that's the solution!